Low serum uric acid levels in patients with multiple sclerosis and neuromyelitis optica: An updated meta-analysis

To evaluate the association between serum uric acid (UA) levels and patients with MS and NMO.

The PubMed, Web of Science and Cochrane Library database were searched for relevant studies. Pooled standardized mean difference (SMD) and 95% confidence interval (CI) were used as effect size. Subgroup analysis was performed by gender, country, disease durations, scores of EDSS, detection method and clinical classification.

A total of 10 case-control studies involving 1537 patients (1308 MS patients, 229 NMO patients) and 908 healthy controls were included. We found the serum UA levels of patients with MS and NMO were significantly lower compared to those of healthy controls (SMD=-0.52, 95%CI,-0.81 to -0.24). In the subgroup analysis, there was no significant difference between serum UA levels in patients and healthy controls in European subgroup (SMD=-0.32, 95%CI,-0.78 to 0.14). Additionally, we found that serum UA levels were higher in MS and NMO patients than in healthy controls in EDSS>3.5 subgroup (SMD=-0.38, 95%CI,-0.58 to -0.19), but not in EDSS≤3.5 subgroup (SMD=-0.35, 95%CI,-0.97 to 0.27). Patients of relapsing group had significant lower serum UA levels than patients of remitting group (SMD=0.70, 95%CI, 0.19-1.21).

Patients with MS and NMO showed lower serum UA levels when compared with healthy controls. Serum UA might be a potential diagnostic biomarker for MS and NMO.